[Bf-committers] Cycles CUDA Toolkit 8 transition

[PerfectionCat]

Hi.

I built in SHA-1: 6353ecb996898b4ce2fe8065130ed1f5ea3b6989 and tried it.
The build did not become slow.
However, blender which built in SHA-1: 70100b4ec7ba299912bf999f15914c0a29125ffd is slow.


With best regards, PerfectionCat.


----- Original Message -----
>From: Sergey Sharybin <sergey.vfx at gmail.com>
>To: PerfectionCat <sindra1961reborn at yahoo.co.jp>; bf-blender developers <bf-committers at blender.org> 
>Date: 2016/8/3, Wed 17:09
>Subject: Re: [Bf-committers] Cycles CUDA Toolkit 8 transition
> 
>
>Interesting.
>
>
>Can you test revision 6353ecb and the one prior to it to see if it's this revision caused the problem?
>
>
>On Wed, Aug 3, 2016 at 12:27 AM, PerfectionCat <sindra1961reborn at yahoo.co.jp> wrote:
>
>Hi.
>>
>>blender which built using a source file at the time of 467e12514e60 in CUDA8 has a shorter time required for rendering of BMW for around 20 seconds.
>>
>>SHA-1-2f5db2e45b7a8af51b15c45bb41f5dcb49ae9d4d is slow.
>>SHA-1-467e12514e60b4130cd0a33b59f53aa4cf7056b6 is fast.
>>
>>Windows 10 pro 64bits
>>
>>Intel i7 6700K 4.4GHz
>>NVIDIA GTX 1070
>>MEMORY 16GB
>>
>>
>>With best regards, PerfectionCat.
>>
>>
>>
>>
>>----- Original Message -----
>>>From: Sergey Sharybin <sergey.vfx at gmail.com>
>>>To: Blender Developers <bf-committers at blender.org>
>>>Date: 2016/8/2, Tue 23:44
>>>Subject: Re: [Bf-committers] Cycles CUDA Toolkit 8 transition
>>>
>>>Hey again,
>>>
>>>Spent majority of the day trying to solve the regression, without much
>>>success. Even simplest kernel needed for BMW scene is about 10% slower.
>>>This is mainly coming from bump nodes. Enabling all other features makes
>>>things even worse performance wise.
>>>
>>>I did some tweaks again to make sure all functions are inlined in the same
>>>manner by CUDA 8.0 as they used to be before. So now PTax output shows
>>>exactly same function, but for some reason spills are just higher with new
>>>toolkit and at the same time stack usage is reasonably slower. Not sure yet
>>>what's going on here and think we'd better leave this alone for until
>>>official toolkit is released.
>>>
>>>For the time being i've switched buildbots to use more complicated setup,
>>>using CUDA 7.5 for all kernels except sm_60 and sm_61 (new generation
>>>cards) and using new toolkit only for new kernels.
>>>
>>>So hopefully now all maxwell and lower crads have same performance as
>>>before. And yet users of new cards can have some degree of GPU rendering.
>>>
>>>
>>>On Mon, Aug 1, 2016 at 6:15 PM, Sergey Sharybin <sergey.vfx at gmail.com>
>>>wrote:
>>>
>>>> Hey everyone,
>>>>
>>>> In order to make Cycles officially support new Pascal cards (GTX 10x0) it
>>>> is crucial to use CUDA Toolkit 8. While it is still in the RC stage we
>>>> started looking into making it official one for Cycles.
>>>>
>>>> There is already some initial work done:
>>>>
>>>> - Tweaks are done to Cycles kernel to have same level of inlined functions
>>>> (new toolkit barely used inlined functions, which resulted in poor
>>>> performance on all cards)
>>>> - New toolkit was installed onto all release environments and buildbots.
>>>>
>>>> So on a positive side, next buildbot's builds will support Pascal cards,
>>>> yay! :)
>>>>
>>>> But unfortunately, while i've managed to keep Kepler cards (GTX760) same
>>>> performance as before, we had a report from Jens in IRC about Maxwell cards
>>>> having a poor performance yet again (in his case, up to 40% worse).
>>>>
>>>> This is really unacceptable, we'll keep working on solution for this
>>>> issue. It might take some time, so just be aware and please be patient :)
>>>>
>>>> I will keep posted here with our progress.
>>>>
>>>> --
>>>> With best regards, Sergey Sharybin
>>>>
>>>
>>>
>>>
>>>--
>>>With best regards, Sergey Sharybin
>>
>>>_______________________________________________
>>>Bf-committers mailing list
>>>Bf-committers at blender.org
>>>https://lists.blender.org/mailman/listinfo/bf-committers
>>>
>>>
>>>
>>_______________________________________________
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>>
>
>
>
>-- 
>
>With best regards, Sergey Sharybin
>
>